// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "paddle/phi/kernels/where_kernel.h"

#include "paddle/phi/core/kernel_registry.h"

namespace phi {

template <typename T, typename Context>
void WhereKernel(const Context& dev_ctx,
                 const DenseTensor& condition,
                 const DenseTensor& x,
                 const DenseTensor& y,
                 DenseTensor* out) {
  const bool* cond_data = condition.data<bool>();
  const T* x_data = x.data<T>();
  const T* y_data = y.data<T>();
  auto x_numel = x.numel();

  T* out_data = dev_ctx.template Alloc<T>(out);
  if (out && out->numel() == 0) {
    return;
  }

  for (int i = 0; i < x_numel; i++) {
    out_data[i] = cond_data[i] ? x_data[i] : y_data[i];
  }
}

}  // namespace phi

PD_REGISTER_KERNEL(where,
                   CPU,
                   ALL_LAYOUT,
                   phi::WhereKernel,
                   float,
                   double,
                   int,
                   int64_t,
                   bool,
                   phi::complex64,
                   phi::complex128) {}
